Deeplinks Blog posts about Printers

This week marks the seventh annual Sunshine Week, a national initiative to promote dialogue about the importance of open government and freedom of information. As our little way to celebrate, EFF has recently posted nearly nine thousand pages of government documents to our site. For the majority of these documents, many of which were previously classified, this is the first time these files have been added to the public domain. The documents were all obtained in conjunction with EFF’s FOIA Litigation for Accountable Government (FLAG) Project, which aims to expose the government's expanding use of new technologies and to protect civil liberties by increasing government transparency.

In a recent review of the HP Color LaserJET CM3530 printer, the magazine Government Computer Newscalled out the use of tracking codes -- which GCN referred to as "a secret spy program" -- as the biggest problem with that printer. GCN found that the yellow dots produced by this printer particularly degraded print quality and noted that some people would question the "logic or appropriateness" of having printers produce the dots at all; it concluded that even people who didn't object to the tracking codes in principle would regret the poor print quality they produced in this case.

Since late 2004, EFF has been warning the public about "printer dots" -- tiny yellow dots that appear on documents produced by many color laser printers and copiers. These yellow dots form a coded pattern on every page the printer produces and can be used to identify specific details about a document; for example, the brand, model, and serial number of the device that printed it and when it was printed. In short, the printer dots are a surveillance tool that can link each printed page to the printer that printed it.

We've long been concerned about the human rights risks of printer tracking dots for anyone who publishes printed works with modern technology. Tracking dots are the secret marks that many popular color laser printers and photocopiers scatter across every document they touch. The marks, almost invisible to the eye, uniquely identify the printer that produced the document, and, as EFF uncovered, can even automatically encode the time and date it was created.

Anonymous self-publication and distribution have been, and remain, a vital political communication channel in many countries. A telltale pattern readable by government officials is a tool that oppressive states everywhere would love to have -- not to mention the general threat to individual privacy countries more respectful of human rights.